1. Field of the Invention:
This invention relates to limb severing apparatus and is more particularly concerned with an apparatus and method of severing limbs from standing trees, primarily for clearing the right-of-way for electrical and telephone overhead wires.
2. Description of the Prior Art
In the past, the cleaning of limbs from standing trees has routinely been accomplished by power companies through the utilization of a vehicle having a boom which carries at its end a gondola. The gondola is positioned adjacent to the limb and a man in the gondola utilizes a chain saw in order to sever the limb. Of course, this procedure is expensive, time consuming and has the danger of dropping the limb onto cables which are strung therebeneath. In some instances, the limbs may be wet and touch wires which carry high voltage. Therefore, there is a danger of electrical shock involved in this procedure.
In the prior art are innumerable devices which, through various means, sever parts of a tree; however, most of these devices are employed to sever the trunk of a tree when the tree is harvested. Attempts have been made to provide the mechanism for severing the limbs of a standing tree. Such mechanisms are, however, quite complicated. The following United States patents disclose the state-of-the-art as known to the inventor:
U.S. Pat. No. 2,663,952 discloses a telescoping boom with a mechanism for clamping a tree. U.S. Pat. No. 3,252,487 discloses a device for delimbing a tree. U.S. Pat. No. 3,443,611 discloses another tree trimming device on an extendible boom. U.S. Pat. No. 3,461,928 discloses a boom mounted saw which cooperates with a clamp mechanism. Still another tree shear is shown in U.S. Pat. No. 3,468,352.
The applicant is also aware of the following additional prior art patents relating to devices for severing trees:
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